Algae Biofuels

Algae bio­fu­els have been tout­ed as being capa­ble of mass-pro­duc­ing liq­uid fuels more sus­tain­ably than ethanol, soy biodiesel or any of the var­i­ous bio­mass, waste or fos­sil-derived liq­uid fuel schemes. Algae bio­fu­els can be grown in fresh or salt-water, can be grown in self-con­tained ponds, and can the­o­ret­i­cal­ly meet U.S. diesel needs using only 1–3 mil­lion acres of land (about 2–5% of the cur­rent­ly fal­low crop­land in the U.S. and less than the size of the state of Con­necti­cut). Diesel is 20% of our nation’s petro­le­um demand, so an area about five times the size of Con­necti­cut could meet all of our oil demand. Algae feeds on CO2.

Sounds great?

That’s not the full story.

Algae bio­fu­els have been explored for decades, with more atten­tion in the past decade. Fun­da­men­tal prob­lems keep it from mak­ing sense… main­ly the need for a con­cen­trat­ed CO2 source and large amounts of water and nutri­ents (nitro­gen and phos­pho­rous). Many of these prob­lems are dis­cussed in the 2017 Bio­fu­el­watch report, Algenol: Case Study of an Unsuc­cess­ful Algae Bio­fu­els Ven­ture. See also: Hard Lessons From the Great Algae Bio­fu­el Bub­ble (2017 arti­cle in Green Tech Media on the lack of progress in mak­ing algae bio­fu­els work)

One prob­lem with com­mer­cial­ly pro­duc­ing biodiesel from algae is that it needs a con­cen­trat­ed and plen­ti­ful CO2 source. This requires hitch­ing this “green” indus­try to dirty pol­lu­tion sources that ought to be rapid­ly phased out, such as coal pow­er plants. This mar­riage of algae biodiesel to coal has result­ed in such pub­lic rela­tions arti­cles with titles like “Algae — like a breath mint for smoke­stacks.” To obtain a puri­fied CO2 source from pow­er plant exhaust, mas­sive amounts of invest­ment dol­lars would need to be spent on “clean coal” gasi­fi­ca­tion sys­tems – per­pet­u­at­ing coal use (and the relat­ed destruc­tion from min­ing, burn­ing and waste dis­pos­al). Such mon­ey would go much fur­ther if invest­ed in gen­uine clean ener­gy strategies.

To make the indus­try com­mer­cial­ly viable, researchers have pur­sued biotech vari­eties, which could be par­tic­u­lar­ly dan­ger­ous if released into nature. Some algae biodiesel pro­pos­als involve aqua­cul­ture-style oper­a­tions in open ocean waters, which could have harm­ful eco­log­i­cal effects, espe­cial­ly if biotech algae is used.

Water and nutri­ent use would also be extreme, mak­ing any seri­ous scal­ing up of algae bio­fu­els quite unsustainable.

The Nation­al Research Coun­cil of the Nation­al Acad­e­my of Sci­ences has explored this in a 2012 report called “Sus­tain­able Devel­op­ment of Algal Bio­fu­els,” which found the following:

Bio­fu­els made from algae are gain­ing atten­tion as a domes­tic source of renew­able fuel. How­ev­er, with cur­rent tech­nolo­gies, scal­ing up pro­duc­tion of algal bio­fu­els to meet even 5 per­cent of U.S. trans­porta­tion fuel needs could cre­ate unsus­tain­able demands for ener­gy, water, and nutri­ent resources. Con­tin­ued research and devel­op­ment could yield inno­va­tions to address these chal­lenges, but deter­min­ing if algal bio­fu­el is a viable fuel alter­na­tive will involve com­par­ing the envi­ron­men­tal, eco­nom­ic and social impacts of algal bio­fu­el pro­duc­tion and use to those asso­ci­at­ed with petro­le­um-based fuels and oth­er fuel sources. This report was pro­duced at the request of the U.S. Depart­ment of Energy.

Key Findings

• Based on a review of lit­er­a­ture pub­lished until the author­ing of this report, the com­mit­tee con­clud­ed that the scale-up of algal bio­fu­el pro­duc­tion suf­fi­cient to meet at least 5 per­cent of U.S. demand for trans­porta­tion fuels would place unsus­tain­able demands on ener­gy, water, and nutri­ents with cur­rent tech­nolo­gies and knowl­edge. How­ev­er, the poten­tial to shift this dynam­ic through improve­ments in bio­log­i­cal and engi­neer­ing vari­ables exists.
  
• Sus­tain­able devel­op­ment of algal bio­fu­els would require research, devel­op­ment, and demon­stra­tion of the fol­low­ing:
  
  
  
  • Algal strain selec­tion and improve­ment to enhance desired char­ac­ter­is­tics and bio­fu­el productivity.
    
  • An ener­gy return on invest­ment (EROI) that is com­pa­ra­ble to oth­er trans­porta­tion fuels, or at least improv­ing and approach­ing the EROIs of oth­er trans­porta­tion fuels.
    
  • The use of waste­water for cul­ti­vat­ing algae for fuels or the recy­cling of har­vest water, par­tic­u­lar­ly if fresh­wa­ter algae are used.
    
  • Recy­cling of nutri­ents in algal bio­fu­el path­ways that require har­vest­ing unless coprod­ucts that meet an equiv­a­lent nutri­ent need are produced.
    
  • A nation­al assess­ment of land require­ments for algae cul­ti­va­tion that takes into account cli­mat­ic con­di­tions; fresh­wa­ter, inland and coastal saline water, and waste­water resources; sources of CO2; and land prices is need­ed to inform the poten­tial amount of algal bio­fu­els that could be pro­duced eco­nom­i­cal­ly in the Unit­ed States.
    
  • Algal bio­fu­els have the poten­tial to con­tribute to improv­ing the sus­tain­abil­i­ty of the trans­porta­tion sec­tor, but the poten­tial is not yet real­ized. Addi­tion­al inno­va­tions that require research and devel­op­ment are need­ed to real­ize the full poten­tial of algal biofuels.
    
  • Algal strain devel­op­ment is need­ed to enhance traits that con­tribute to increas­ing fuel pro­duc­tion per unit resource use, reduc­ing the envi­ron­men­tal effects per unit fuel pro­duced, and enhanc­ing eco­nom­ic via­bil­i­ty. Improve­ments in bio­mass or prod­uct (lipid, alco­hol, or hydro­car­bons) yield, cul­ture den­si­ty, nutri­ent uptake, ease of har­vest, and pho­to­syn­thet­ic effi­cien­cy are some of the improve­ments that would improve sus­tain­abil­i­ty of algal biofuels.
    
  • Engi­neer­ing solu­tions to enhance algae cul­ti­va­tion, to facil­i­tate bio­mass or prod­uct col­lec­tion, and to improve pro­cess­ing of algae-derived fuels can increase the EROI and reduce the GHG emis­sions of algal bio­fu­el production.
    
  
  

  
  The envi­ron­men­tal, eco­nom­ic, and social effects of algal bio­fu­el pro­duc­tion and use have to be com­pared with those of petro­le­um-based fuels and oth­er fuel alter­na­tives to deter­mine whether algal bio­fu­els con­tribute to improv­ing sus­tain­abil­i­ty. Such com­par­i­son will be pos­si­ble only if thor­ough assess­ments of each step in the var­i­ous path­ways for algal bio­fu­el pro­duc­tion are conducted.

  
  
  
  
  • Read the full report here
    
  • Fact­sheet on the report
    
  
  

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  Break­ing: Large-scale pro­duc­tion of bio­fu­els made from algae pos­es sus­tain­abil­i­ty con­cerns; fur­ther inno­va­tions need­ed to reach full potential

  
  

  
  BY GLOBAL JUSTICE ECOLOGY PROJECT | OCTOBER 24, 2012 · 11:05 AM

  
  

  
  Note: The fol­low­ing is an overview of an upcom­ing report from the Nation­al Research Coun­cil. The con­cerns raised over large-scale algal bio­fu­el pro­duc­tion are seri­ous, and high­light the dan­gers of many false solu­tions to cli­mate change: increased use of essen­tial resources (i.e., fresh water, land), depen­dence on syn­thet­ic or mined inputs such as nitro­gen and phos­pho­rus, and com­plete obscu­ri­ty as to whether or not the tech­nol­o­gy will result in decreased car­bon emis­sions. Fur­ther, as the below arti­cle notes, genet­ic engi­neer­ing, or “strain improve­ment,” is need­ed to increase the effi­cien­cy and pro­duc­tiv­i­ty of algae. Giv­en the threats that GMO food crops and GE trees pose, the last thing we need is GE algae col­o­niz­ing our rivers, lakes and oceans. Even­tu­al­ly, we will have to real­ize that the only viable sub­sti­tute for fos­sil fuel use is a dras­tic decrease in our con­sump­tion pat­terns and sys­temic trans­for­ma­tion of the cur­rent neolib­er­al eco­nom­ic system.

  
  

  
  -The GJEP Team

  
  

  
  Octo­ber 24, 2012. Source: Nation­al Research Council

  
  

  
  WASHINGTON — Scal­ing up the pro­duc­tion of bio­fu­els made from algae to meet at least 5 per­cent — approx­i­mate­ly 39 bil­lion gal­lons — of U.S. trans­porta­tion fuel needs would place unsus­tain­able demands on ener­gy, water, and nutri­ents, says a new report from the Nation­al Research Coun­cil. How­ev­er, these con­cerns are not a defin­i­tive bar­ri­er for future pro­duc­tion, and inno­va­tions that would require research and devel­op­ment could help real­ize algal bio­fu­els’ full potential.

  
  

  
  Bio­fu­els derived from algae and cyanobac­te­ria are pos­si­ble alter­na­tives to petro­le­um-based fuels and could help the U.S. meet its ener­gy secu­ri­ty needs and reduce green­house gas emis­sions, such as car­bon diox­ide (CO2). Algal bio­fu­els offer poten­tial advan­tages over bio­fu­els made from land plants, includ­ing algae’s abil­i­ty to grow on non-crop­lands in cul­ti­va­tion ponds of fresh­wa­ter, salt water, or waste­water. The num­ber of com­pa­nies devel­op­ing algal bio­fu­els has been increas­ing, and sev­er­al oil com­pa­nies are invest­ing in them. Giv­en these and oth­er inter­ests, the Nation­al Research Coun­cil was asked to iden­ti­fy sus­tain­abil­i­ty issues asso­ci­at­ed with large-scale devel­op­ment of algal biofuels.

  
  

  
  The com­mit­tee that wrote the report said that con­cerns relat­ed to large-scale algal bio­fu­el devel­op­ment dif­fer depend­ing on the path­ways used to pro­duce the fuels. Pro­duc­ing fuels from algae could be done in many ways, includ­ing cul­ti­vat­ing fresh­wa­ter or salt­wa­ter algae, grow­ing algae in closed pho­to­biore­ac­tors or open-pond sys­tems, pro­cess­ing the oils pro­duced by microal­gae, or refin­ing all parts of macroal­gae. The committee’s sus­tain­abil­i­ty analy­sis focused on path­ways that to date have received active atten­tion. Most of the cur­rent devel­op­ment involves grow­ing select­ed strains of algae in open ponds or closed pho­to­biore­ac­tors using var­i­ous water sources, col­lect­ing and extract­ing the oil from algae or col­lect­ing fuel pre­cur­sors secret­ed by algae, and then pro­cess­ing the oil into fuel.

  
  

  
  The com­mit­tee point­ed out sev­er­al high-lev­el con­cerns for large-scale devel­op­ment of algal bio­fu­el, includ­ing the rel­a­tive­ly large quan­ti­ty of water required for algae cul­ti­va­tion; mag­ni­tude of nutri­ents, such as nitro­gen, phos­pho­rus, and CO2, need­ed for cul­ti­va­tion; amount of land area nec­es­sary to con­tain the ponds that grow the algae; and uncer­tain­ties in green­house gas emis­sions over the pro­duc­tion life cycle. More­over, the algal bio­fu­el ener­gy return on invest­ment would have to be high, mean­ing more ener­gy would have to be pro­duced from the bio­fu­els than what is required to cul­ti­vate algae and con­vert them to fuels.

  
  

  
  The com­mit­tee found that to pro­duce the amount of algal bio­fu­el equiv­a­lent to 1 liter of gaso­line, between 3.15 liters to 3,650 liters of fresh­wa­ter is required, depend­ing on the pro­duc­tion path­way. Replen­ish­ing water lost from evap­o­ra­tion in grow­ing sys­tems is a key dri­ver for use of fresh­wa­ter in pro­duc­tion, the com­mit­tee said. In addi­tion, water use could be a seri­ous con­cern in an algal bio­fu­el pro­duc­tion sys­tem that uses fresh­wa­ter with­out recy­cling the “har­vest” water.

  
  

  
  To pro­duce 39 bil­lion liters of algal bio­fu­els, 6 mil­lion to 15 mil­lion met­ric tons of nitro­gen and 1 mil­lion to 2 mil­lion met­ric tons of phos­pho­rus would be need­ed each year if the nutri­ents are not recy­cled, the report says. These require­ments rep­re­sent 44 per­cent to 107 per­cent of the total nitro­gen use and 20 per­cent to 51 per­cent of the total phos­pho­rus use in the U.S. How­ev­er, recy­cling nutri­ents or uti­liz­ing waste­water from agri­cul­tur­al or munic­i­pal sources could reduce nutri­ent and ener­gy use, the com­mit­tee said.

  
  

  
  Anoth­er resource that could lim­it the amount of algal bio­fu­els pro­duced is land area and the num­ber of suit­able and avail­able sites for algae to grow. Appro­pri­ate topog­ra­phy, cli­mate, prox­im­i­ty to water sup­plies — whether fresh­wa­ter, inland saline water, marine water, or waste­water — and prox­im­i­ty to nutri­ent sup­plies would have to be matched care­ful­ly to ensure suc­cess­ful and sus­tain­able fuel pro­duc­tion and avoid costs and ener­gy con­sump­tion for trans­port­ing those resources to cul­ti­va­tion facil­i­ties. If the suit­able sites for grow­ing algae are near urban or sub­ur­ban cen­ters or coastal recre­ation areas, the price of those lands could be pro­hib­i­tive. A nation­al assess­ment of land require­ments for algae cul­ti­va­tion that takes into account var­i­ous con­cerns is need­ed to inform the poten­tial amount of algal bio­fu­els that could be pro­duced eco­nom­i­cal­ly in the U.S.

  
  

  
  One of the pri­ma­ry moti­va­tions for using alter­na­tive fuels for trans­porta­tion is reduc­ing green­house gas emis­sions. How­ev­er, esti­mates of green­house gas emis­sions over the life cycle of algal bio­fu­el pro­duc­tion span a wide range; some stud­ies sug­gest that algal bio­fu­el pro­duc­tion gen­er­ates less green­house gas emis­sions than petro­le­um-based fuels while oth­er stud­ies sug­gest the oppo­site. These emis­sions depend on many fac­tors in the pro­duc­tion process, includ­ing the amount of ener­gy need­ed to dewa­ter and har­vest algae and the elec­tric­i­ty sources used.

  
  

  
  The com­mit­tee empha­sized that the cru­cial aspects to sus­tain­able devel­op­ment are posi­tion­ing algal growth ponds close to water and nutri­ent resources and recy­cling essen­tial resources. With prop­er man­age­ment and good engi­neer­ing designs, oth­er envi­ron­men­tal effects could be avoid­ed, the com­mit­tee said. Exam­ples include releas­ing har­vest water in oth­er bod­ies of water and cre­at­ing algal blooms and allow­ing har­vest water to seep into ground water.

  
  

  
  For algal bio­fu­els to con­tribute a sig­nif­i­cant amount of fuels for trans­porta­tion in the future, the com­mit­tee said, research and devel­op­ment would be need­ed to improve algal strains, test addi­tion­al strains for desired char­ac­ter­is­tics, advance the mate­ri­als and meth­ods for grow­ing and pro­cess­ing algae into fuels, and reduce the ener­gy require­ments for mul­ti­ple stages of pro­duc­tion. To aid the U.S. Depart­ment of Ener­gy in its deci­sion-mak­ing process regard­ing sus­tain­able algal bio­fu­el devel­op­ment, the com­mit­tee pro­posed a frame­work that includes an assess­ment of sus­tain­abil­i­ty through­out the sup­ply chain, a cumu­la­tive impact analy­sis of resource use or envi­ron­men­tal effects, and cost-ben­e­fit analyses.

  
  

  
  The report was spon­sored by the U.S. Depart­ment of Ener­gy. The Nation­al Acad­e­my of Sci­ences, Nation­al Acad­e­my of Engi­neer­ing, Insti­tute of Med­i­cine, and Nation­al Research Coun­cil make up the Nation­al Acad­e­mies. They are pri­vate and inde­pen­dent non­prof­it insti­tu­tions that pro­vide sci­ence, tech­nol­o­gy, and health pol­i­cy advice under an 1863 con­gres­sion­al char­ter. Pan­el mem­bers, who serve pro bono as vol­un­teers, are cho­sen by the Acad­e­mies for each study based on their exper­tise and expe­ri­ence and must sat­is­fy the Acad­e­mies’ con­flict-of-inter­est stan­dards. The result­ing con­sen­sus reports under­go exter­nal peer review before com­ple­tion. For more infor­ma­tion, vis­it http://dels.nas.edu/Report/Sustainable-Development-Algal-Biofuels/13437